Inaccurate Mass Props Calc in Asm WF4

[tdekon]

We have an issue with Pro/E referencing the wrong CS with respect to it's location in an assembly.


Here is our current process:


1. In assembly, activate part requiring CG analysis


2. Select Analysis>Model>Mass Properties


3. In Analysis box, select CS we want to measure CG relative to (FED130_CS) & Compute.


Results:


CENTER OF GRAVITY with respect to FED130_CS coordinate frame:
X Y Z 2.0845767e-01 6.2798746e+00 1.7171229e-01 INCH


The XYX results above are not correct and are actually relative to the default CS of the part, even though it clearly states FED130_CS.


We cannot determine what we are doing wrong. Our workaround has been:


1. Activate part in assembly


2. Creat new CS at FED130_CS location


3. Open part


4. Calculate mass properties again, selecting the newly created CS.


Any advice is appreciated. We want to eleiminate this extra step of creating a new CS for every part as we have thousands of parts in our vehicle and be confident that when it gives us a CG relative to a stated CS in assembly mode, we can trust it.





Thanks in advance,


Terry

 

[tdekon]

123 Views and no responses? Is this something nobody has come across before?


Terry

 

[Ray Ellender]

Sounds like a bug. Suggest you contact PTC customer support (Who will probably want you to send the model and then wait until WF6 (sorry Creo) until it is fixed, but you never know, it may be fixed in a cut of WF4)

 

[mechg]

The reason you are getting the wrong answer is in the first line of your method. The only reliable way of getting the mass properties right is to open the component you want the mass properties of, then carry out the measure. If your CSYS's are all called FED_130CS, you could record a mapkey for this task, then all you need to do is to highlight the component in the model tree, run the mapkey and the m_p file for it will appear in your working directory.

Regards,

Rod Giles
Senior Design Engineer
Polaris Industries